Multimorbidity of communicable and non-communicable diseases in low- and middle-income countries: A systematic review

Objective The aim of this systematic review is to analyse existing evidence on prevalence, patterns, determinants, and healthcare challenges of communicable and non-communicable disease multimorbidity in low- and middle-income countries (LMICs). Methods PubMed, Cochrane, and Embase databases were searched from 1st January 2000 to 31st July 2020. The National Institute of Health (NIH) quality assessment tool was used to critically appraise studies. Findings were summarized in a narrative synthesis. The review was registered with PROSPERO (CRD42019133453). Results Of 3718 articles screened, 79 articles underwent a full text review of which 11 were included for narrative synthesis. Studies reported on 4 to 20 chronic communicable and non-communicable diseases; prevalence of multimorbidity ranged from 13% in a study conducted among 242,952 participants from 48 LMICS to 87% in a study conducted among 491 participants in South Africa. Multimorbidity was positively associated with older age, female sex, unemployment, and physical inactivity. Significantly higher odds of multimorbidity were noted among obese participants (OR 2.33; 95% CI: 2.19–2.48) and those who consumed alcohol (OR 1.44; 95% CI: 1.25–1.66). The most frequently occurring dyads and triads were HIV and hypertension (23.3%) and HIV, hypertension, and diabetes (63%), respectively. Women and participants from low wealth quintiles reported higher utilization of public healthcare facilities. Conclusion The identification and prevention of risk factors and addressing evidence gaps in multimorbidity clustering is crucial to address the increasing communicable and non-communicable disease multimorbidity in LMICs. To identify communicable and non-communicable diseases trends over time and identify causal relationships, longitudinal studies are warranted.

Multimorbidity is clearly defined, descriptive analyses was done to characterize the study sample, inclusion and exclusion criteria was clear, information on missing data provided, sample size large enough, power of study is high Multimorbidity was defined-use of multimorbidity wheel, no information on missing data handeling, selection bias may have occurred due to convinient sampling (mine workers) Multimorbidity was defined, selection bias may be present as the study excluded discharged and diseased patient's data as missing, adequate sample size and strong power of study multimorbidity was clearly defined, self-report leads to chance of recall bias, inclusion and exclusion criteria clearly defined, sample size calculated and reported, missing data information missing multimorbidity was clearly defined-two definitions given, missing data handeling was reported, exclusion and inclusion criteria clear, self-report concordant and discordant multimorbidity was clearly defined, information on missing data was reported+ missing data handeling, self-report may have resorted in reporting bias multimorbidity was well-defined, missing data reported and handeling information provided, self -report may have resulted in recall bias, confounders adjusted Multimorbidity was well-defined, sample size calculations were provided, outcome and dependent variables were defined, adjustments for age and gender were done, self-report, no information on missing data handling was provided Multimorbidity was well-defined, outcome and dependent measures were clearly outlines and defined, there was no information on the handling of missing data, adjustment for age and HIV status was sone    Objectives 4 Provide an explicit statement of the objective(s) or question(s) the review addresses.

METHODS
Eligibility criteria 5 Specify the inclusion and exclusion criteria for the review and how studies were grouped for the synthes

Item # Checklist item
Information sources 6 Specify all databases, registers, websites, organisations, reference lists and other sources searched or the date when each source was last searched or consulted.
Search strategy 7 Present the full search strategies for all databases, registers and websites, including any filters and limit Selection process 8 Specify the methods used to decide whether a study met the inclusion criteria of the review, including ho record and each report retrieved, whether they worked independently, and if applicable, details of autom Data collection process 9 Specify the methods used to collect data from reports, including how many reviewers collected data from independently, any processes for obtaining or confirming data from study investigators, and if applicable the process.
Data items 10a List and define all outcomes for which data were sought. Specify whether all results that were compatibl study were sought (e.g. for all measures, time points, analyses), and if not, the methods used to decide 10b List and define all other variables for which data were sought (e.g. participant and intervention character assumptions made about any missing or unclear information. Study risk of bias assessment 11 Specify the methods used to assess risk of bias in the included studies, including details of the tool(s) us each study and whether they worked independently, and if applicable, details of automation tools used i Effect measures 12 Specify for each outcome the effect measure(s) (e.g. risk ratio, mean difference) used in the synthesis o

Synthesis methods
13a Describe the processes used to decide which studies were eligible for each synthesis (e.g. tabulating th and comparing against the planned groups for each synthesis (item #5)).
13b Describe any methods required to prepare the data for presentation or synthesis, such as handling of m conversions.
13c Describe any methods used to tabulate or visually display results of individual studies and syntheses.
13d Describe any methods used to synthesize results and provide a rationale for the choice(s). If meta-analy model(s), method(s) to identify the presence and extent of statistical heterogeneity, and software packag 13e Describe any methods used to explore possible causes of heterogeneity among study results (e.g. subg 13f Describe any sensitivity analyses conducted to assess robustness of the synthesized results.

Reporting bias assessment
14 Describe any methods used to assess risk of bias due to missing results in a synthesis (arising from rep Certainty assessment 15 Describe any methods used to assess certainty (or confidence) in the body of evidence for an outcome.

Study selection
16a Describe the results of the search and selection process, from the number of records identified in the se in the review, ideally using a flow diagram.
16b Cite studies that might appear to meet the inclusion criteria, but which were excluded, and explain why t

Study characteristics
17 Cite each included study and present its characteristics.

Risk of bias in studies
18 Present assessments of risk of bias for each included study.

Results of individual studies
19 For all outcomes, present, for each study: (a) summary statistics for each group (where appropriate) and precision (e.g. confidence/credible interval), ideally using structured tables or plots.

Results of syntheses
20a For each synthesis, briefly summarise the characteristics and risk of bias among contributing studies.
20b Present results of all statistical syntheses conducted. If meta-analysis was done, present for each the su (e.g. confidence/credible interval) and measures of statistical heterogeneity. If comparing groups, descri 20c Present results of all investigations of possible causes of heterogeneity among study results.
20d Present results of all sensitivity analyses conducted to assess the robustness of the synthesized results Reporting biases 21 Present assessments of risk of bias due to missing results (arising from reporting biases) for each synth Certainty of evidence 22 Present assessments of certainty (or confidence) in the body of evidence for each outcome assessed.

Discussion
23a Provide a general interpretation of the results in the context of other evidence.
23b Discuss any limitations of the evidence included in the review.

Section and Topic
Item # Checklist item 23c Discuss any limitations of the review processes used.
23d Discuss implications of the results for practice, policy, and future research.

OTHER INFORMATION
Registration and protocol 24a Provide registration information for the review, including register name and registration number, or state 24b Indicate where the review protocol can be accessed, or state that a protocol was not prepared.
24c Describe and explain any amendments to information provided at registration or in the protocol. Support 25 Describe sources of financial or non-financial support for the review, and the role of the funders or spons Competing interests 26 Declare any competing interests of review authors.
Availability of data, code and other materials 27 Report which of the following are publicly available and where they can be found: template data collectio studies; data used for all analyses; analytic code; any other materials used in the review. For more information, visit: http://www.prisma-statement.org/